Cleaning or washing printing inks and other organic residues from printing plates, rollers, and other machine parts within the graphics industry has been effected by a variety of means over the years. However, the cleaning liquids employed frequently contain dangerous substances, such as low boiling aromatic solvents, carcinogenic materials and other substances that entail considerable risks to the individuals handling these substances. In addition to safety risks, typical cleaning liquids in this regard can pose considerable environmental issues. In particular, the use of petroleum distillates or aromatic compounds such as xylene, toluene, or naphthalene-based agents is widespread. The significant health, safety and environmental dangers of these substances are well known. Such compounds are, in general, highly volatile and exhibit low flash points.
Because of the health hazards associated with these volatile solvents, various efforts have been made to produce cleaning solutions that are free of such solvents. U.S. Pat. No. 5,104,567 to Staehr, the teachings of which are incorporated herein by reference in their entirety, reveal some exemplary cleaning solutions which are free of solvents. Staehr proposes a solution of vegetable oil and an emulsifier as an ink cleaner. Further reference is made to U.S. Pat. Nos. 5,792,278 and 5,814,163, both to Wojcik, the teachings each of which are incorporated herein by reference in their entirety, reveal improved ink cleaning compositions.
It is an object of the present invention to provide an ink cleaning solution which is safer to handle and more environmentally friendly than cleaning solutions based upon volatile solvents, but which is also a more effective cleaning agent than previously taught solvent substitutes. These and other objects of this invention will be apparent to those skilled in the art upon reading the disclosure contained herein.